1. Technical Field
The present invention relates to a rewritable optical disk recording method for a variable-length packet writing system that sequentially receives, from a host computer, data that is accumulated in a buffer memory, and that sequentially reads and then writes the accumulated data via an optical pickup that follows up at a predetermined speed.
2. Prior Art
For the recording of data on a rewritable optical disk, generally, a fast interface, a bus, is used to transmit target data from a host computer to a recording apparatus. Thereafter, the recording apparatus temporarily stores the recording data in a buffer memory from which, in accordance with a fixed-length packet writing system, the data is sequentially read before being written on an optical disk using an optical pickup.
When due to scratches or dust on an optical disk, variable-length packet write system recording errors occur while data are being recorded, the information actually recorded in a PMA does not match the contents of the recording data that are provided for a track. Thus, at this point, media errors occur, i.e., deterioration in the use of the optical disk occurs.
To resolve this problem, an example information recording/reproduction apparatus has been proposed (refer to the Unexamined Japanese Patent Application Publication No. Hei10-143980).
When the recording of an optical disk is halted due to the occurrence of a servo error, such as an off-track, an information recording/reproduction apparatus stores the current error address, and begins to record predetermined dummy data near that address in the remaining portion of the area that has been allocated as a track. For an explanation of this process, a detailed flowchart in FIG. 5 of the reference publication should specifically be referred to.
That is, when an error occurs during recording, the information recording/reproduction apparatus records up to 300 blocks, the minimum length of one track, of dummy data, records the error information in the PMA, and halts the processing.
[Problems to be Solved]
It is highly probable that errors due to scratches or dust on the surface of an optical disk will occur not merely on one occasion but repetitively. In other words, it is highly probable that when an error has occurred during recording, an error will again occur during a current additional writing process for recording dummy data.
However, when an error occurs during the additive writing process for dummy data, the conventional information recording/reproduction apparatus simply performs an error process and halts the processing (step S27 in FIG. 5), and no consideration is given for an error that occurs during the additional writing process. In other words, the conventional information recording/reproduction apparatus can not cope with an error that occurs during the additive writing of dummy data.
Assume that when an error occurs during the additive writing process the additive writing process is repeated from the beginning. Then, if ten errors occur repetitively, ten tracks will be employed for the additive writing of dummy data, and the number of available tracks will be reduced considerably. Further, if an error occurs after the additive writing of 100 blocks has been completed, the additive writing process will be continued for the remaining 200 blocks to complete the recording for one track, and thereafter, the additive writing process will again be performed for another track (300 blocks). As a result, blocks that originally were available will also be used for the additive writing process, and the data recordable area will be reduced by an amount equivalent to the size of these blocks.
To resolve the conventional shortcomings, it is one objective of the present invention to provide a recording method for a rewritable optical disk whereby, even when an error has occurred during an error process (in the prior art, an additive writing process), the additive writing of data to an optical disk is enabled without the number of tracks used for the error process being increased, and without the number of available blocks being reduced more than is necessary.
[Means for Solving the Problems]
To achieve this objective, according to a first aspect of the invention, provided is a recording method for a rewritable optical disk having a variable-length packet write system that sequentially accumulates, in a buffer memory, data received from a host computer, and that sequentially reads the data and writes the data on the rewritable optical disk via an optical pickup, which follows up at a predetermined speed, the recording method comprising:
a first step of, when an error occurs during the recording of the rewritable optical disk, determining whether a track currently being used for recording is a reserve track;
a second step of, when the track currently being used is a reserve track, changing the recording system for the track that is currently being used from a variable-length packet write system to a fixed-length packet write system employing an arbitrary length;
a third step of, when the track currently being used is not a reserve track, determining whether an area equal to or greater than 300 blocks, which is the minimum length of one track, has been employed for recording before the occurrence of the error;
a fourth step of, when at least 300 blocks have not yet been employed, continuing to record dummy data using the fixed-length packet write system until at least 300 blocks, including packets currently being used, have been recorded;
a fifth step of, when an error has occurred during the recording of the dummy data at the fourth step, continuously recording dummy data so as to add one fixed-length packet having the arbitrary length; and
a sixth step of recording link blocks when at the third step it is ascertained that at least 300 blocks have been employed for recording, when according to the fourth step up to at least 300 blocks of the dummy data have been recorded using the fixed-length packet write system, or when according to the fifth step the dummy data has been recorded up to the added packet. Null or silent data is recorded as the dummy data.
According to the invention including this feature, when an error occurs during the recording of an optical disk, the track recording system is changed from the current variable-length packet write system to a fixed-length packet write system employing an arbitrary length. Then, the dummy data is continuously recorded using a fixed-length packet having the arbitrary length until at least a total of 300 blocks have been recorded along the track, including the recorded packet. Finally, the link blocks (a RUN-OUT1 block, a RUN-OUT2 block and a LINK block) are recorded. At this time, dummy data is continuously recorded, so that each time an error occurs during the recording of dummy data, one arbitrary length, fixed-length packet is added. By repeating this process, the dummy data are recorded using the fixed-length packet write system until a count of at least 300 blocks has been reached along the track, and then, finally, the link blocks (a RUN-OUT1 block, aRUN-OUT2 block and a LINK block) are recorded.
Specifically, when an error attributable to a variable-length packet write system occurs during the recording of an optical disk, the track recording method is changed from the current variable-length packet write system to a fixed-length packet write system employing an arbitrary length, and an error process is performed. When an error again occurs during the error process, one fixed-length packet having the designated arbitrary length is added to continue the recording of dummy data. And finally, when at least 300 blocks of dummy data have been recorded, the link blocks are recorded.
That is, the recorded data is correctly read only up to the packet immediately preceding the occurrence of the error. However, since the data is recorded in the same form as that used for the normal track for the link blocks, a new track can be added, and used, after it is determined along which track the dummy data has been recorded. Furthermore, even when an error again occurs during the error process, the dummy data is continuously recorded while one fixed-length packet is added, and finally, the link blocks are recorded. Therefore, while the number of blocks wherein the dummy data are recorded may exceed 300, only one track is required for the error process. In other words, since only one track is required for the error process, a savings can be realized during the recording of the data for the track. In addition, since dummy data is continuously recorded, even when an error again occurs during the error process, compared with the conventional information recording/reproduction apparatus, no more available blocks, i.e., free area, will be employed than is necessary. That is, according to the present invention, even when another error occurs during an error process, for the recording of dummy data, only the addition of the minimum number of blocks having an arbitrary fixed-length packet length is required.
According to a second aspect of the invention, a recording method is provided for a rewritable optical disk using a variable-length packet write system that sequentially accumulates, in a buffer memory, data received from a host computer, and that sequentially reads and writes the data on the rewritable optical disk via an optical pickup that follows up at a predetermined speed, the recording method comprising:
a first step of changing the recording system for a track that is currently being used from a variable-length packet write system to a fixed-length packet write system having an arbitrary length;
a second step of determining whether blocks equal to or greater than a predetermined number have been employed for recording before the error occurred;
a third step of, when a number of blocks equal to or greater than the predetermined number has not been employed, continuously recording dummy data in accordance with the fixed-length packet write system until the total number of blocks, including packets that are currently employed, reaches the predetermined number of blocks;
a fourth step of, when an error occurs during the recording of the dummy data, continuously recording dummy data by adding a fixed-length packet having the arbitrary length; and
a fifth aspect of finally recording link blocks when at the second step it has been ascertained that the predetermined number of blocks has been employed for recording, when at the third step it has been determined that the dummy data has been recorded using the fixed-length packet system until the predetermined number of blocks has been reached, or when at the fourth step the dummy data has been recorded up to the packet that is added.
According to this invention that includes this feature, while the recorded data can be correctly read only up to the packet immediately preceding the occurrence of an error, data is recorded in the same form as a normal track along which the link blocks are recorded. Thus, following the track along which the dummy data has been recorded, data can be recorded along a new track that is added. In addition, since the dummy data is continuously recorded, even when an error has again occurred during the error process, until finally the link blocks are recorded, only one track is required for the error process. In other words, since only one track is employed for the error process, the tracks used for recording data are not wasted. Furthermore, since the dummy data is continuously recorded, even when an error has again occurred during the error process, compared with the conventional information recording/reproduction apparatus, no more of the available blocks will be consumed than is necessary.